COLUMN IEQ APPLICATIONS FIGURE 4C Example of hybrid control technique. Room Exhaust Valve Room Supply Valve Supply Air Total Exhaust Air from Room Hood Exhaust Hood Exhaust Total Supply Air to Room DP Sensor Flow Sensor DP Flow Sensor Hood Valve and Controller Room Controller Leakage Air DS Velocity Sensor Door Switch Corridor Chemical Lab T Fume Hood Leakage Air or Sash Sensor Thermostat FIGURE 4D Example of pressure control technique for multiple rooms in a cleanroom/containment suite. DP Legend DP Designated Leakage Flow Cleaner Room 0.06 in. w.c. DS Containment Lab -0.06 in. w.c. Cleanest Room 0.08 in. w.c. Suite Controller DS Corridor 0.00 in. w.c. DS DS DS DS DP General Chemical Lab -0.02 in. w.c. DP Return Air Valve Minor Leaks Through Cracks Pressure DP Differential Sensor DS Door Switch Valve Position Outputs DS DS Airock 0.03 in. w.c. Exhaust Air Valve Supply Air Valve Valve Flow Rate Inputs DP Manifolded or Open to Corridor D ECEM BER 2020 ashrae.org Suite Controller Door Switch Inputs Room Pressure Inputs ASHRAE JOURNAL 69https://www.ashrae.org/